should i have folded this ?

PokerStars No-Limit Hold'em, $0.02 BB (8 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

UTG ($4.81)
UTG+1 ($4.97)
MP1 ($1.89)
MP2 ($4.37)
CO ($2)
Button ($1.81)
SB ($1.92)
Hero ($1.85)

Preflop: Hero is BB with A, 4. CO posts a blind of $0.02.
2 folds, MP1 calls $0.02, 1 fold, CO (poster) checks, 2 folds, Hero checks.

Flop: ($0.07) 4, J, Q (3 players)
Hero checks, MP1 checks, CO checks.

Turn: ($0.07) J (3 players)
Hero checks, MP1 checks, CO checks.

River: ($0.07) 4 (3 players)
Hero bets $0.22, MP1 raises to $1.87, CO folds, Hero calls $1.61 (All-In).

Final Pot: $3.73

Results in white below:
Hero has Ah 4h (full house, fours full of jacks).
MP1 has Kc Jd (full house, jacks full of fours).
Outcome: MP1 wins $3.76.

Zeebo's Theorem - Nobody ever folded a full house.

Reasoning: Nobody is good enough to fold a monster. Most players aren't even good enough to fold a hand that looks like a monster but really isn't.

I dunno, this just seemed relevant.

Hard to say, really. But, any time the board is paired twice and you only have the lower end of the pair, your hand is vulnerable. Most times I'd probably fold and give villain credit for having the J. But at these stakes, you really don't have much to lose.

How about this one? Should i have folded to the turn C/R? I thought he might've thought I was stealing, so he raised

PokerStars No-Limit Hold'em, $0.02 BB (7 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

SB ($1.71)
BB ($2.81)
Hero ($2.01)
MP1 ($4.91)
MP2 ($8)
CO ($1)
Button ($3.02)

Preflop: Hero is UTG with Q, Q. CO posts a blind of $0.03.
Hero raises to $0.08, 4 folds, SB calls $0.07, 1 fold.

Flop: ($0.21) 5, 4, A (2 players)
SB checks, Hero checks.

Turn: ($0.21) A (2 players)
SB checks, Hero bets $0.12, SB raises to $0.3, Hero calls $0.18.

River: ($0.81) T (2 players)
SB bets $1.33 (All-In), Hero folds.

Final Pot: $0.81

Results in white below:
SB doesn't show.
Outcome: SB wins $2.14.

I'm actually more likely to call the checkraise here, or even shove over than fold... ever.

Hand 1: I guess Zeebo's really applies here. The board is double paired and while you hit it for the full house, it's the lower pair and someone might have the bigger one. My immediate thought here is that with $0.07 in the pot on the river your RELATIVE hand strength does not mandate you betting. You could just check/call. If you check the opponent might not have the idea that you have a hand that you can call a big bet with and just bet $0.20 or something which you can then call and get off the hook cheaply. As played when he bets all-in - he probably has either a J or a 4 (that is, the full house). Since there are two Jacks unaccounted for and only 1 4 you are most likely to lose. Your bet is big enough that he's not shoving all-in here as a bluff imo. I'm not saying I would find a fold here either, but it's probably the best decision.

Hand 2: Bet flop. Your turn bet is smallish and he might think you're just taking a stab at it. On the river I think he's shoving for value - but he might be doing that with a T thinking he's best. Your hand is underrepresented and I think his flop and turn checks are just a bit too weak for him to hold an ace a lot of the time. He could easily think you are holding a 4 or 5. I'd probably call here.